Heat the oil in a large pan or flameproof casserole dish and fry the beef in 2 batches until brown. Remove from the pan.
Add the butter, garlic, onions and mushrooms to the pan and fry for a few minutes. Return the beef to the pan.
Add the tomato purée, Worcestershire sauce, beer, stock, bay leaf and herbs. Stir well and bring it all to the boil.
Simmer it all on a low heat for an hour and a half until the meat is tender (thicken if necessary). Remove the lid and let it cool slightly.
Heat the oven to 200˚C / 180˚C fan / Gas 6.
Put the filling mixture into the pie dish.
Roll out the pastry for the top of the pie. Cut 4 long thin strips from the edge of the pastry. Brush the edge of the dish with the beaten egg. Use the strips to place around the edge of the pie dish, and brush with egg.
Place the pastry over the filling and the strips lightly. Trim any pastry that hangs over the edge.
If you also want pastry on the bottom, take another packet of pastry and roll it and put it in the bottom of a metal dish. Then Follow the instructions above and put the dish and the metal tray before putting it in the oven.
Press and crimp the edges and use any remaining pastry to decorate the top of the pie.
Brush with the beaten egg and place in the oven. Bake for around 25-30 minutes until the top is golden brown and the filling is piping hot.
